I recently tried exactly that with MacInCloud. XCode and Delphi XE4's PAServer is now automatically installed by MacInCloud so I had few issues hooking up my Windows and Delphi environment.
What I found was that running and debugging in the iOS simulator on the Mac in the cloud worked fine. However as my upload speed was quite slow a compilation took some considerable time. Each compilation seemed to require an upload of about 17MB for the app and another 50MB for the debug symbols.
There is no way of plugging in your iPhone into the mac in the cloud and MacInCloud therefore recommend that you use a further cloud provider (TestFlightApp.com) to deploy the app to your device. I couldn't test using the TestFlightApp service as I have not signed up for the required developer account with Apple and so cannot deploy to physical devices at all.
All in all, if I was doing serious work I would either buy a Mac or pay for faster upload speeds but despite that I found it an very educational experience.